Dehydration is a condition in which water in a living body decreases below the individual's normal functioning level. Dehydration often occurs when an individual is exerting energy for extended periods of time, an individual intakes little or no water, or the temperature rises to a point where an individual cannot excrete enough sweat to maintain their normal body temperature. Persons that regularly exert themselves in low humidity and/or high temperature conditions and/or for extended periods of time are prone to experience dehydration or dehydration symptoms. Elderly persons and children are also especially prone to experience dehydration or dehydration symptoms.
When a person experiences a dehydrated condition, the individual's ability to perform tasks may begin to deteriorate. For example, in the case of long distance endurance athletes, an individual that becomes dehydrated by loss of as little as 2% body weight may begin to have their performance impaired. Losses in excess of 5% of body weight can decrease the capacity of an individual to perform a task by as much as 30%.